What about the VISA situation for Canadians (to stay longer than 3 months)?
I think a B2 is good for six months; that's what I was planning to seek if our team was ever accepted, and I haven't had a problem getting them in the past whenever I traveled south on business. Of course, I would still be very interested to hear from any successful YC teams from Canada.
Of course, your mileage may vary, but this is what I've read from other people.